在實際應用場景中會遇到一個項目連接多個數據庫的情況，下面來做一個簡單的配置。
作者在開發過程中把數據庫的配置放在了properties文件中，如圖：
spring-mybatis配置放在了了spring-dao.xml文件中
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
<context:property-placeholder ignore-unresolvable="true" location="classpath:jdbc.properties"/>
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" >
<property name="driverClass" value="${jdbc.driver}" />
<property name="jdbcUrl" value="${jdbc.url}" />
<property name="user" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="maxPoolSize" value="30"/>
<property name="minPoolSize" value="10"/>
<property name="autoCommitOnClose" value="false"/>
<property name="checkoutTimeout" value="10000"/>
<property name="acquireRetryAttempts" value="2"/>
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="typeAliasesPackage" value="com.senxing.po"/>
<property name="mapperLocations" value="classpath:mapper/*xml"/>
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
<property name="basePackage" value="com.senxing.dao"/>
</bean>
<!--第二個數據源配置-->
<bean id="dataSource2" class="com.mchange.v2.c3p0.ComboPooledDataSource" >
<property name="driverClass" value="${jdbc.test.driver}" />
<property name="jdbcUrl" value="${jdbc.test.url}" />
<property name="user" value="${jdbc.test.username}" />
<property name="password" value="${jdbc.test.password}" />
<property name="maxPoolSize" value="30"/>
<property name="minPoolSize" value="10"/>
<property name="autoCommitOnClose" value="false"/>
<property name="checkoutTimeout" value="10000"/>
<property name="acquireRetryAttempts" value="2"/>
</bean>
<bean id="sqlSessionFactory1" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource2"/>
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="typeAliasesPackage" value="com.senxing.po"/>
<property name="mapperLocations" value="classpath:mapper/backdao/*xml"/>
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory1"/>
<property name="basePackage" value="com.senxing.backdao"/>
</bean>
</beans>
如上所示，我們分別配置了兩個 dataSource，兩個sqlSessionFactory，關鍵的地方在於MapperScannerConfigurer 的配置——使用sqlSessionFactoryBeanName屬性，注入不同的sqlSessionFactory的名稱，這樣的話，就爲不同的數據庫對應的 mapper 接口注入了對應的 sqlSessionFactory。
現在就可以用了